# CYCLIC SYMMETRY Error when Slave/Master contain some nodes from fixed surface **URL:** \ **Category:** Uncategorized\ **Created:** [February 9, 2021, 7:09am UTC](https://calculix.discourse.group/t/cyclic-symmetry-error-when-slave-master-contain-some-nodes-from-fixed-surface/440 "2021-02-09T07:09:43Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![vossi](https://avatars.discourse-cdn.com/v4/letter/v/e9bcb4/32.png) [@vossi](https://calculix.discourse.group/u/vossi)\ **Post date:** [February 9, 2021, 7:09am UTC](https://calculix.discourse.group/t/cyclic-symmetry-error-when-slave-master-contain-some-nodes-from-fixed-surface/440/1 "2021-02-09T07:09:43Z")
Good Morning, I have some trouble with symmetry. I have 1/4th of a symmetry plate which is attacked by gravity. I created a support at the green surface, a Master Surface and a Slave Surface with nodes. ![image](https://global.discourse-cdn.com/free1/uploads/calculix/original/1X/b576dfe02994d5eaad865becacc7b5e271ddea6f.png) I want to use symmetry, thus I used the \*CYCLIC SYMMETRY Card. Unfortunately, it doesn’t work. I get the following error message. > ERROR in cascade: the DOF corresponding to node 1 in direction 1 is detected on the dependent side of a MPC and a SPC. If I understand it correctly, it is not allowed to have the same points in my Master/Slave and in my support surface because they have different ways to calculate the boundaries. However, if I remove the support the spooles solver read the input and starts. Here is some part of my file: > \*Surface, Name=Master, Type=Node > Internal-1\_Master > \*Surface, Name=Slave, Type=Node > Internal-2\_Slave > > \*TIE,CYCLIC SYMMETRY,POSITION TOLERANCE=1.,NAME=T1 > Slave, Master > \*CYCLIC SYMMETRY MODEL, N=4,NGRAPH=4 > 0.,0.,0.,0.,0.,-1. > > \*Step > \*Static > > \*Boundary, op=New > \*Boundary > Internal\_Selection-1\_Disp\_rot-1, 1, 1, 0 > Internal\_Selection-1\_Disp\_rot-1, 2, 2, 0 > Internal\_Selection-1\_Disp\_rot-1, 3, 3, 0 > > \*Dload > Solid\_part-1, GRAV, 9810, 0, 0, -1 Is there a way to solve my problem with symmetry? I read something about the \*EQUATION card but I haven’t really understood the use of it and how to use it. Calculix: 2.16 OS: Windows GUI: PrePoMax v0.9 I wish you all a nice day! ---
**Author:** ![dichtstoff](https://avatars.discourse-cdn.com/v4/letter/d/dec6dc/32.png) [@dichtstoff](https://calculix.discourse.group/u/dichtstoff)\ **Post date:** [February 9, 2021, 8:28am UTC](https://calculix.discourse.group/t/cyclic-symmetry-error-when-slave-master-contain-some-nodes-from-fixed-surface/440/2 "2021-02-09T08:28:36Z")
There could be trouble, If you use nodes with \*Boundary and the same nodes with another card like in a set for \*TIE master & slave (except \*Cload,…) ---
**Author:** ![vicmw](https://avatars.discourse-cdn.com/v4/letter/v/6de8d8/32.png) [@vicmw](https://calculix.discourse.group/u/vicmw)\ **Post date:** [February 9, 2021, 10:24am UTC](https://calculix.discourse.group/t/cyclic-symmetry-error-when-slave-master-contain-some-nodes-from-fixed-surface/440/3 "2021-02-09T10:24:54Z")
You can use \*BOUNDARY (“a SPC”) on nodes of the master surface but not the slave (“the dependent side of a MPC”). It’s not needed on slave nodes since the slaves automatically follow their corresponding masters’ constraints. ---
**Author:** ![vossi](https://avatars.discourse-cdn.com/v4/letter/v/e9bcb4/32.png) [@vossi](https://calculix.discourse.group/u/vossi)\ **Post date:** [February 9, 2021, 11:24am UTC](https://calculix.discourse.group/t/cyclic-symmetry-error-when-slave-master-contain-some-nodes-from-fixed-surface/440/4 "2021-02-09T11:24:44Z")
Thank you for your answer. And actually it makes sence. I removed all the constrains from the slave and it works now. Thanks a lot! ![image](https://global.discourse-cdn.com/free1/uploads/calculix/original/1X/86cf492f8369129c830750e95d0134c27c9f25e3.png) ---
**Author:** ![kyle.w](https://avatars.discourse-cdn.com/v4/letter/k/bbe5ce/32.png) [@kyle.w](https://calculix.discourse.group/u/kyle.w)\ **Post date:** [May 21, 2021, 10:04am UTC](https://calculix.discourse.group/t/cyclic-symmetry-error-when-slave-master-contain-some-nodes-from-fixed-surface/440/5 "2021-05-21T10:04:21Z")
Hi Could you give more information as to how you removed the constraint from the slave? ---
**Author:** ![vossi](https://avatars.discourse-cdn.com/v4/letter/v/e9bcb4/32.png) [@vossi](https://calculix.discourse.group/u/vossi)\ **Post date:** [May 21, 2021, 10:12am UTC](https://calculix.discourse.group/t/cyclic-symmetry-error-when-slave-master-contain-some-nodes-from-fixed-surface/440/6 "2021-05-21T10:12:58Z")
You use the nodes to set the boundary conditions and not the surface. You can do it by selecting all of them by surface. After that you can deselect single nodes which are on the slave surface. And this is what I have done. It wasn’t very handy but ok for my needs. ---
**Author:** ![kyle.w](https://avatars.discourse-cdn.com/v4/letter/k/bbe5ce/32.png) [@kyle.w](https://calculix.discourse.group/u/kyle.w)\ **Post date:** [May 21, 2021, 11:21am UTC](https://calculix.discourse.group/t/cyclic-symmetry-error-when-slave-master-contain-some-nodes-from-fixed-surface/440/7 "2021-05-21T11:21:57Z")
Ah right 🙂 That makes sense now. I appreciate the assisstance. Thanks a lot!